US2269423A

US2269423A - Valve mechanism

Info

Publication number: US2269423A
Application number: US359034A
Authority: US
Inventors: Frank S Barks; Victor G Klein
Original assignee: Lincoln Engineering Co
Current assignee: Lincoln Engineering Co
Priority date: 1940-09-30
Filing date: 1940-09-30
Publication date: 1942-01-13
Anticipated expiration: 1959-01-13

Description

2 Jan.13,1942. 2 F, KS HAL 2,269,423

VALVE MECHANISM Filed Sept. 50, 1940 s Sheets-Sheet 1' FIG.|.4,; 99

95 v t I l 53 j .5 I 5 20? a? 305 xm'dwigg gaw a 37 Jan 13, 1942. F. s. BARKS 'EIAL VALVE MECHANISM 5 Sheets-Sheet 5 Filed Sept. 30, 1940 \ANAMMMFALHQ Patented Jan. 13, 1942 UNITE-o PATENT OFFICE.

l I I I lei-11k sees in ,v'icto; a 7st. ass,

Me, assi'gi ors Li' ncolniEn ieenn Com- ""y; St. Denis, MEL, a corporation 'ofMis'souri Application'Septemlier30, 1940, Serial No. 359,034

is chins. 7 nor lime) This, invention relates to valve mechanisms, and with regard to certainmore specific features, to. a; full-stroke valve mechanism ior reciprocati s en s-o invention described in the United States patent of \Victor G. Klein for Valve mechanism, No.;2,-2:15-,852.

Among the several objects of the invention may be noted the-provision ,ot a full-stroke valve mechanism of the type shown in said patent,- in which very compact structure is effected, and in which the forces between an operating piston and the toggle mechanism which itgoperates are substantially. co-planar, thereby avoidingunde sirab le inisalignr'n'ent or cocking of saidpiston; and the provision o'f a; deviceoi the class deib d in w h Wear and leakage ,are; reduc d by said more advantageous. disposition ofg Darts;

pointed out hereinafter I V I, H

" may comprises the, ele- Other objects will be in part obvious and in part i'n've tion. accord merits and combinationsof, elements, features; of

construction, and arrangements of parts which is anlimproyement .upon that Fig. '11 is a view correspondihgtodf'ig. 51m 1 showing mane-mauveform or the nvention;

Fig. 12 is a horizontal section taken on line l2:/ l2.'o'fFig."5'; and, Fig. '13 is a fragmentary section of a piston:

showing an alternative form. I,

, Similair reference "characters indicate correspo'ndiiig parts thfoughout the several views of the drawings.

' quired more careful piston design forbest re'--.

will be exemplified in the structiires hereinafter described, and thes'cope application of which ,will he indicated in thejollowing claims In the a companyin drawings, V illustrated several of various possible embodimet-It's of the inv ntion, 3 1

lg, 1 is vertical Sec in which are hon show ng the sites-- tiori ap'plied to a reciprocating air or fluid engine,

the piston being sfhoWl-iilibi Fig.2 isa Fig. 1', cover parts Being removed to show the valve gear; I 7 h I Fig.- 3 is a horizontal section taken on line 3=-3 L .v 7 M Fig; 4 is a view-similar to Fig; 1 showing the piston almost down and a toggle mechanism on center about to trip a valve; v

Fig. 5 is a; fragmentaryyiew similar to Fig. 2' showing the conditions of Fig. 4;

Fig. 6- is avi'ew simmer to Fig. 4, showing the piston in final downward with nae toggle mechanism tripped otereent'er with the valve moved to its opposite position;

7' is a, fragmentary view similar to Fig. 5;

but showing the conditions of'Fig". 6;

Fig. 8 is a vertical sectiontaken on line 8 8 ofiFig'. 1; H

Fig 9 is a vertical section taken on line" 9-4 ofiig'. 3; i

of Fig. 1;

Fig. 1,0,- is a segments-y right-hand elevation i ragmentery left side .eievatignrf In said K-lei'n patent, the 'piston which was I waspconnected to the toggle mechanism by a "pin i t on one side of the iston, This placed the piston-operating forces in aplane which wasoifset, with respect to the forces in the toggle mecha nism and tendedto cock the-piston. This results. ,The present application discloses an arrangement whereby these forces are made coplanar thus makingit possible to manufacturethe piston at less cost. All side thrust andcocks mg onthe.piston. -is eliminated on'the present design, While/at the same time the designzis made [more compact:

there'iis shown at numeral I an engine cylinder hay ng an upper-head 3andalower head 5 con-.-

and carries a stuffing gland 9 through which re ciprocates a hollow7 piston rod 1 l.- A pump. outlet isprovidd f t, o The piston rod ll extends down tohoperateithe pump, being connected with connectingiod 203 by threads 2, 05., The con- 7 I netting rad 2'03"is some, as shown at 2151 It is attecl'ied to spump'rdd '4. I

Within the engine cylinder l is areciprocating piston 13 which is fixed upon the end of the piston rod I l'. slidablewithih the hollow piston rod 1 I isea valve trip rod 2| which extends'upwa'r'd fthroughza packing gland 21 in the head 3 and downward into said hollow portion 201. Here it roiiided with avfixed head l9. Since the pist'o 3,, hollow flpiston. rod ll, connecting rod 203 pump rfd jl reciprocate together, they jmq s a fu it with respect to the head l9 on the ip rodll. ,the fi s D int of differentiation (if the present constructiony over that 1 in Klein patent, is that the lost;

eson connectio bet e the head I9 and, the

h 1 is below the pack- Referring, now, more particularlyv to Fig; -1,

der 20]; rather than.

der I. An advantage of this construction is that since the lost-motion connection l9, 291 is below the packing 9, the sliding piston rod H which goes through the packing may be made of a reduced diameter and consistent with certain volumetric ratios desired in cylinder 2El| and depending upon the intrusion of a certain size of the rod H.

The trip rod 2| has affixed at its end above the packing 21 a member providing a lower shoulder 25. Above the shoulder 25 is a reduced portion 29 and above this reduced portion is a member forming a second shoulder 3|, which slides in and is guided by a bearing 32 in a cap 33. The portions 2|, 25, 29 and 3| aremovable up and down as a unit, a pin 6 holdingthem together.

At numeral 34 (Fig. 3) is shown a piston movably fitted into a guide 35 which carries therein a spring-pressed packing 31. The guide 35 is in the side Wall of an air tight casing 4| which forms an extension from the head 3. The casing is enclosed and sealed shut by means of a'cover 44. There is thus provided a casing in which the internal pressure may be raised by leading in air or other fluid under operating pressure over passage 1| .(see Fig. 10). Thus the piston 34 tends normally to be forced out from the guide 35.

At this point may be pointed out .thesecond distinction from said Klein patent which consists in placing the piston 34 so that its motion is lateral or normal with respect to the trip rod 2|. This permits of the co-planar relationship above mentioned and later to be particularized. The casing 4| is cored 'or drilled to form an exhaust port 43 and two

feed ports

45 and 41. The feed port 45 passes to the upper end of the cylinder I, and port 41 passes to the lower end of said cylinder by way of a connecting pipe 49 and a passage 5| in the lower head 5. The pipe 49 is clamped in position between the heads 3 and 5 by the tension in the studs 1, suitable packing 53 being used for sealing purposes.

The portion of the casing 4| adjacent the ends of the

passages

43, and 41 is machined circularly in a vertical plane to receive a circular valve plate 55. The plate 55 carries an exhaust port 43A which forms the valved end for the exhaust port 43; and also inlet ports 45A and 41A which form the inlet valve ports for the

feed ports

45 and 41, respectively. Packing 8 is used to sea the plate 55. I

The purpose of the valve plate 55 is to obtain a convenient hard-surfaced member for sealing cooperation with a D-valve 51. Valve 51 rides on the plate 55 in such a way as to connect the exhaust port 43A either with the inlet port 45A or the inlet 41A, depending upon position. The port 45A or 41A which is uncovered is thus placed in communication with the fluid under pressure inside of the enclosing casing and cover 4| and 44. Since the

passages

45 and 41 communicate with the opposite ends of the cylinder it is clear that themotion of the D-valve 51 controls distribution of fluid (air under pressure in the present example) to the opposite ends of the cylinder. At the time that a given

passage

45 or 41 is open to its respective cylinder end, the

other passage

45 or 41 is in communication with the exhaust passage 43 by way of the hollow inside of the D-valve. For example in Figs. 1 and l the D-valve is in its upper position in which the passage 45-is delivering fluid to the upper end.

of the cylinder and the passage 41 is in communication with the exhaust passage 43.

A plan view of the valve assembly is shown in Fig. 8. It consists of a member l0 on the plate having side portions 6| for longitudinally guiding the D-valve 51 (see also Fig. 9). The side portions 6| are connected by raised bridge portions or end stops for limiting the stroke of said D-valve 51. The stops being raised from the plate 55 serve for the reception of foreign material which the valve may push toward the ends of its stroke. Such foreign material then does not build up in any corner to unseat the valve or to shorten its stroke, but is pushed under and out of the respective stop 65. This space "is very accurately surfaced in connection with the bottom surface of the D-valve, in order to obtain a good seal. Any substantial distortion, such as might be employed by directly bolting down the plate 55, might cause leakage between valve 51 and its seat. The packing means 8 used under the disc 55 serves also to limit distorting stress.

Spring holding cylinders 209 are held on the side members 6|. Springs 2 therein force detent balls 2|3 into receiving pockets 2| 5 in the Dvalve 51. Thus the D -va1ve is forced to assume a predetermined position at each end of its stroke.

Fluid under pressure in the housing 4| tends to hold the D-valve 51 against its seat on the plat 55. Fluid is brought in over the passage 1| by means of an inlet pipe 13 which communicates with a suitable supply of fluid under pressure (not shown).

The D-valve 51 is operated by a trip shoe 14 which is in the shape of a fork, the legs 15 of which include openings v11 around the reduced portion 29 associated with the trip rod 2|. The reduced portion 29 is of a length which is somewhat greater than the distance between the outside surfaces of the legs 15. The trip shoe 14 therefore has a lost motion engagement with respect to the trip rod 2| and may slide between the limits determined bythe heads 25 and 3|.

The distance between the insides of legs 15 is greater than the length of the outside length of the D-valve 51, so that there is also lost motion between here. As shown in Figs. Land 6, the legs 15 of the trip shoe 14 are long enough to contact with. the ends of D-valve 51, and they are separated an amount to provide said lost motion. Part of the lost motion is shown as being taken up in Fig. 4.

Extending from the .back of the trip shoe is a pin 19 which reaches through an opening 8| of a stationary supporting plate 80. The opening 8| is large enough to accommodate the necessary vertical and lateral movements of the pin .19. The plate includes also cut-away portion H for clearing a pin to be described.

The purpose of the plate 80 is, with a fixed member 81, to support a linkage shown in Figs. 1-7. The plate 80 and support 81 support a pivot 89 atthe left and guide slots 9| at the right (Fig. 3). A clevis shaped member 93 oscillates on the 2,269,423 3" gle linkage over-centers upward and moves the pivot 89. --A clevis shaped connecting -rod 95 is 1 articulated to the cle-vis93 byfmeans of a-loose connection with-the pin 19. This clevis'95 carries in its right-handforked portion. a pin 91 which slidesin the guides 91. Around the-pin 91 and -5 19 (from the trip shoe l4) and thetwo clevises'9-3 10 and;95 is loose enough to accommodate sideward swing of the pin 19 necessitated by the fact that the, end of the clevis 93 moves to the 'rig-htin-an arc (Fi 12).

The two clev-

ises

93 and 95 function as a toggle 15.:-

having one end pivoted at 8 9 and the other end pivoted =on.the sliding pin 91. Since the sliding pin. 9}! is pivoted to thelyoke, any centering of th toggle links 93 and 95 will coincide with an inward (right) position of the piston 34 (Fig. -5)-, 2Q-

and conversely a broken position of the toggle corresponds to an outward (left) position of the piston '34 (Figs. 2and -'7).

Operation of the device is as follows:

Assume that the driving piston 13- is up as of the yoke need only be such'as to clear the toggle links 9% and 95111 all positions, and that shown in Fig. 1, and that it has reset the valve 51 so that fluid under pressure is flowing from the inside of the casing 41 into the open port 45 and to a point above the piston. 'Iheipiston will then descend, carrying with it the :hollow 3U- piston rod i and the hollow connecting member 203. The hollow portion 201 then traversesthe stationary head 19- of the then stationary. trip rod 2L The fluid under pressure at this time forces the piston 34 to the leftso that theyoke199 35,

has collapsed the toggle links 93, 95 into the upward angled-position shown in Fig. 2.

Travel of the piston .13 downward finally #results in all of the lost motion being taken up at the recess 201, that is, the head [9 is contacted 4o;

by the upper end of 201. When this occurs, down: ward motion is transmitted tothe trip rod 2t, and the shoulder 3| begins-to tone down the shoe 14. Thus the shoe is pulled down until the extension pin 19 straightens the toggle linkage 93,

overto the left, thus anglin down the toggles links 93 and 95 into'the position shown in Figs. 6

and '7. This further forces down the shoe M with a snap action due to the connection between the toggle linkage with. theshoe through the pin- 19. The result is as shown in Figs. 6 and 7 where- W in the shoe 14 has taken up the clearance between it and the D-valve and then has moved the D- valve to the Fig. 6 position. Upon this occurring, the fluid under pressure is delivered toa point below the piston l3 via the port 41 and. pipe 49' while the fluid above the piston is exhausted over

ports

45, 45A, 43A and 43. i.

The action on the upward stroke is the reverse of that described above. The piston l3 moves to the upper end of its stroke, taking up lost mo- 7,9,

tionwith respect to the head l9, and thereafter the trip rod 2| is moved upwardly causing. the

-

toggle links

93 and 95 to straightenout.. This draws'in the piston 34 against the fluid under pressure. in the chamber 41-. Thereafter the tog- 7.5;

Some clearance remains between-the s shoe 14'upward with snap action to take upth'e clearance between the shoe I4 and the b -yalve 51 and thereafter to move the valve with a snap movement to the initial position shown in Figs.

1, 2 and 3.

An examination of Figs. 3 and 12 willrshow that the center line of the piston 34 and central plane of the toggle mechanism are coextensive and that therefore there is no cooking of the piston 34. Thisreduces the wear on the cylindric portions of the guide 35 with a resulting better seal of the piston 34'. Insaid Klein application the piston which corresponds to piston 3l-herein transmits its force through a side lug which introduces some-cocking side wear.

Another feature of the present invention is that the center line of the toggle mechanism and the piston 34'. are crosswise :of the centerline of the valveand trip 'rod assembly and of the travel of the shoe M, so that a more compact arrangementisaccomplished.

Fig. 11 showshow the yoke 99 may have substituted-therefor an equivalent one-sided yoke 2 H. This is to illustrate the point that the shape 91. Another reason for compactness is the fact 3 thatthe toggle mechanism is carried within the arch of the yoke 99 oritssequivalent 2H.

The bifurcated end of the link "93 and the central tongue of, the l=ink-95 prov-idean interlock for maintaining alignment. This is also true of the bifurcated end of the link9'5 andthe yoke 99.

Although the

links

93 and 95 are referred to herein as toggle links, they may also be con 'sidered in the: following light:

The link 99 is a short oscillating lever on. the center 8-9 and is pivoted by means of the pin- -19 to the member 95 which functions as a connect- This slider is yoked ing rod with the slider 91. by means of the yoke 99 with the piston slider;

theyok'e being arched around the link mechanism.

It will be understood that the fluid used for operating the engine and valve may been, or.

. oil, or thelike. 1

In Fig. 13' is shown how the construction 0 still" further be simplified. This is, done by sub-,-

stituting for the piston 34 a drag link 25f reach- 1 ,ing through an opening 253 in a body 255' which is capped shut by means of a cap 257. A spring 259 reacts against a shoulder 26I around the opening 253, and also against a head -263fon the drag link 25!. The spring is of the compression variety and normally biases the drag link 25l to the'left in Fig. 13. This construction introduces a spring for overcentering the: toggle linkage. This Fig. 13 and. accompanying description is in= sorted for the purpose of'showing that a mejichanical equivalent of the piston 34 may involve a spring; andrurt'her to emphasize the savestageous linkage fcrhi disclosedherein.

In view or the above, it will'b'e seen that the' several objects of the invention are achieved and I f other'advantageous' resultsatt'ained.

As many changes could be made ,in the has constructions without departing from the scope v ofth'e' invention, it is intended that an matter" contained. in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. A valve mechanism comprising a valve, a trip shoe having a lost-motion engagement with the valve, a trip rod having a lost-motion engagement with the trip shoe, a toggle linkage having its center line lying crosswise with respect to the motion of the shoe and comprising two toggle links, one of which has a fixed pivot and the other of which has a sliding pivot, said toggle links being pivoted to one another by means of a pivot connection with said trip shoe,

and means biasing said movable pivot toward the fixed pivot.

2. A valve mechanism comprising a valve, a trip shoe having an engagement with the valve, a toggle linkage having a center line lying crosswise with respect'to the trip shoe motion and comprising two toggle links, one of which has a fixed pivot and the other of which has a sliding pivot, said toggle links being also pivoted to one another by means of a pivot connection with said trip shoe, and means biasing said sliding'pivot toward the fixed pivot, said last-named means comprising a pressure-operated piston, and a yoke connecting said piston with said movable pivot means;

3. A valve mechanism comprising a valve, a 'trip shoe having a lost-motion engagement with the valve a trip rod having a lost-motion engagement withthe trip shoe, a toggle linkage having a center line lying crosswise with'respect to the valve motion and comprising two toggle links, one of which has a fixed pivot and the other of which has a sliding pivot, said toggle links being pivoted to one another by means of a pivot connection with said trip shoe, and means biasing said movable pivot toward the fixed pivot, said last-named means comprising a pressureoperated piston, and a yoke connecting said piston with said movable pivot means, said yoke surrounding at least part of the toggle linkage and being in its plane of action.

4. Valve gear comprising an air-tight compart ment having superatmosphere pressure of fluid therein, a valve-operating shoe operative along one line in said compartment, a piston member in sealing engagement with an opening in the wall of the compartment and movable substantially at right angles to the movement of the shoe, a toggle linkage having a fixed pivot and a sliding pivot and an oscillating pivot between said fixed and sliding pivots, said oscillating pivot being articulated to said shoe, and a yoke connecting the sliding piston and said sliding pivot.

5.'Valve gear comprising a fluid-tight com partment having superatmo'spheric pressure therein, a valve-operating shoe operative along one line in said compartment, a piston member in sealing engagement with an opening in the Wall of the compartment and movable substantially at'right anglesto the movement of the shoe, a toggle linkage having a fixed pivot and a sliding pivot and an oscillating pivot between said fixed and sliding pivots, said oscillating pivot being attached to said shoe, and a yoke connecting the sliding piston'and the movable pivot, the pivot connection with the shoe being loose enough to provide for lateral movement of the shoe normal to its axial movement.

6. In a valve mechanism, a valve-operating shoe movable in a given direction, a reciprocating piston movable substantially at right angles to said shoe, a pivot pin extending from the shoe into the plane of piston movement, a yoke pivoted to the piston and passing around the pivot pin in any position that the latter may assume in its reciprocation, a fixed pivot, a sliding pivot, an oscillating member on the fixed pivot and a connecting rod attached to said sliding pivot, said yoke being also attached to said sliding pivot, said oscillating member and said connecting rod being pivoted by means of the pivot from the shoe.

'7. In a valve gear, a fixed support, an oscillating member pivoted at one point in said support, a connecting member having one end pivoted to said oscillating member and the other pivoted to a slide in the support, a sliding piston adjacent to' the fixed pivot, and a connecting member betweensaid sliding piston and said sliding pivot.

8. In a valve gear, a fixed support, an oscillatv in the Operating plane of said oscillating and connecting members and shaped to clear said oscillating and connecting members in all positions of the same.

9. In a valve gear, a fixed support, an oscillating member pivoted at one point in said support, a connecting member having one end pivoted to said oscillating member and the other pivoted to a slide,-a sliding piston adjacent to the fixed pivot, and a connecting member between said sliding piston and said sliding pivot, said lastnamed member comprising a yoke lying in the plane of said oscillating member and the connecting member and shaped to clear said oscillating and connecting members in all positions ofthese members, and a'valve-operating shoe movable substantially'at right angles to the line of movement of said piston and having a pivot forming the connection between the oscillating and connecting members.

10. Valve gear mechanism comprising spaced frame plates,'a fixed pivot pin between said plates at one point, an oscillating member on said pivot having the form of a clevis, a connecting rod having also the form of a clevis with a tongue in the clevis of the oscillating member, a sliding pin in the clevis of the connecting rod, guides for the sliding pin in said spaced frame plates, a sliding piston adjacent the fixed pivot formed also as a clevis, and a yoke pivoted in the clevis of the piston and to the sliding pivot within the clevis of the connecting rod, a shoe sliding normally to the line of action of the piston, said shoe having a pivot pin reaching into the connection between the oscillating member and the connecting rod.

11. Valve gear mechanism comprising spaced frame plates, a fixed pivot pin between said plates at one point, an oscillating member on said pivot having the form of a clevis, a connecting rod having also the form of a clevis with a tongue in the clevis of the oscillating member, a sliding pin in the clevis of the connecting rod, guides for the sliding pin in said spaced frame plates, a sliding piston adjacent the fixed pivot formed also as a clevis, and a yoke pivoted in the clevis of the piston and to the sliding pivot within the clevis of the connecting rod, a shoe sliding normally to the line of action of the piston, said shoe having a pivot pin reaching into the connection between the oscillating member and the connecting rod, the connection including enough lost-motion to permit the lateral movement required of the shoe by the oscillations of the oscillating member;

12. Valve gear mechanism comprising spaced frame plates, a fixed pivot pin between said plates at one point, an oscillating member on said pivot having the form of a clevis, a connecting rod having also the form of a clevis with a tongue in the clevis of the oscillating member, a sliding pin in the clevis of the connecting rod, guides for the sliding pin in said spaced frame plates, a sliding piston adjacent the fixed pivot formed also as a clevis, and a yoke pivoted in the clevis of the piston and to the sliding pivot within the clevis of the connecting rod, a shoe sliding normally to the line of action of the piston, said shoe having a pivot pin reaching into the connection between the oscillating member and the connecting rod, the connection including enough lost-motionto permit the lateral movement required of the shoe by the oscillations of the oscillating member, one of the fixed plates having an opening accommodating the extension from the shoe in all of its required positions.

frame plates, a sliding'piston adjacent the fixed pivot formed as a clevis, a yoke pivoted to the clevis of the piston and to the sliding pivot within the clevis of the connecting rod, a'shoe sliding normally to the line of action of the piston, said shoe having a pivot pin reaching into the connection between the oscillating member and the connecting rod, the connection including enough lost-motion to permit the movement required of the shoe by the oscillations of the oscillating member, and a fluid-tight compartment surrounding the mechanism having a wall'opening accommodating the piston.

15. Valve gear mechanism comprising spaced frame plates, a fixed pivot pin between said plates at one point, an oscillating member on said pivot having the form of a clevis, a connecting rod having also the form of a clevis with a tongue in the clevis of the oscillating member, a sliding pin in the clevis of the connecting rod, guides for the sliding pin in said spaced frame plates, a sliding piston adjacent the fixed pivot formed as a clevis,

, and a yoke pivoted to the clevis of the piston and 13. Valve gear mechanism comprising spaced frame plates, a fixed pivot pin between said plates at one point, an oscillating member on said pivot having the form of a clevis, a connecting rod having also the form of a clevis with a. tongue in the clevis of the oscillating member, a sliding pin in the clevis of the connecting rod, guides for the sliding pin in said spaced frame plates, a sliding piston adjacent the fixed pivot formed as a clevis, and a yoke pivoted to the clevis of the piston and to the sliding pivot within the clevis of the connecting rod.

14. Valve gear mechanism comprising spaced frame plates, a fixed pivot pin [between said plates at one point, an oscillating member on said pivot having the form of a clevis, a connecting rod having also the form of a clevis with a tongue in the clevis of the oscillating member, a sliding pin in the clevis of the connecting rod, guides for the sliding pin in said spaced to the sliding pivot within the clevis of the connecting rod, said yoke comprising a hollow memher having an opening therethrongh accommodatlng the oscillating member and connecting rod in all positions thereof.

16. Valve gear mechanism comprising spaced frame plates, a fixed pivot pin between said plates at one point, an oscillating member on said pivot having the form of a clevis, a con- 7 necting rod having also the form of a clevis with a tongue in the clevis of the oscillating member, a sliding pin in the clevis of the connecting rod, guides for the sliding pin in said spaced frame plates, a sliding piston adjacent the fixed pivot formed as a clevis, and a yoke pivoted to the clevis of the piston and to the sliding pivot within the clevis of the connecting rod, said connecting rod comprising an arch-shaped member reaching around the oscillating member and the connecting rod in one of their extreme positions.

FRANK S. BARKS. VICTOR G. KLEIN.